Summary of Work: Patients with chronic granulomatous disease (CGD) frequently develop pulmonary infections. In many patients with CGD an accurate diagnosis is difficult to establish due to the scarcity of organisms in pathologic specimens. This study assesses, in a retrospective manner, all procedural as well as diagnostic data in patients with CGD and pulmonary disease. The study assesses the utility of sputum, bronchoscopy (lavage and transbronchial biopsy), computed tomography-guided transthoracic needle aspiration, and open lung biopsy in establishing either a definitive or presumptive pulmonary diagnosis. The goal is to establish a diagnostic algorithm for pulmonary procedures in patients with CGD based on relative invasiveness and diagnostic yield. Data are being collected for analysis from 65 patients over a 15- year period.